I've seen somewhere that there's an edupup release, but I've already got puppy installed, is there a TuxPaint package around? My kids would be eternally grateful if you could point me in the right direction..

it's not packaged as a .pet or .pup, but i'm assuming it's an "alien" package.

download it to your computer, then start the puppy package manager, click "to run the Petget package manager", then click the small button, 2nd from the top, "Or, if you have downloaded a Pet package, official or unofficial....", then change directory to where you downloaded & click to install.